Currently, unmanned aerial vehicles (UAV) have been widely applied to the modern society, and because the UAV does not require human pilot aboard, it can perform much more dangerous tasks. The most widely application field of the UAV is reconnaissance, i.e. the UAV transmits the aerial reconnaissance photography back to the ground directly and immediately to determine the reconnaissance target.
The UAV can either used in military applications, such as battlefield reconnaissance and surveillance, positioning, damage assessment, electronic warfare, etc, or in civil applications, such as border patrol, nuclear radiation detection, aerial photography, aviation prospecting, disaster monitoring, traffic patrol, and security monitoring, etc.
According to the field, the optical reconnaissance can be divided into low-altitude reconnaissance, mid-altitude reconnaissance and high-altitude reconnaissance. No matter what types of reconnaissance, a major technology has to be used, namely aerial photography. However, the conventional optical lens used for UAV commonly has deficiencies of small view angle, low resolution, high distortion and the like.